The daughter of actor Robert Montgomery, she began her career in the 1950s with a role on her father's television series Robert Montgomery Presents, and won a Theater World Award for her 1956 Broadway debut in the production Late Love.
In the 1960s, she became known for her role as Samantha Stephens on the ABC sitcom Bewitched.
She has been cited as one of the earliest celebrities to support gay rights and advocate for AIDS victims, volunteering with the AIDS Project Los Angeles and amf AR at the height of the AIDS epidemic.
Montgomery was born on April 15, 1933, in Los Angeles, California, the daughter of actor Robert Montgomery and his wife, Broadway actress Elizabeth Daniel Bryan Montgomery (née Allen), a native of Kentucky. Her great-grandfather, Archibald Montgomery, was born in Belfast, and emigrated to the United States in 1849.
The latter two pregnancies were incorporated into Bewitched as Samantha's pregnancies with Tabitha and Adam Stephens.They moved in together at the end of shooting in 1972. On January 28, 1993, she married for a fourth time to actor Robert Foxworth, after living with him for nearly twenty years. Many references to Patterson, New York, were made on Bewitched throughout the run of the series.The Putnam County town was the site of the Montgomery homestead, and it was also where Elizabeth spent her childhood summers.However, Elizabeth Montgomery's marriage to Bewitched director William Asher was in trouble and the couple had separated by the end of the eighth season, causing severe friction in their professional relationship and ending any possibility of another season.As a consolation to ABC, Montgomery and Asher (under their company name Ashmont, which produced Bewitched) offered a half-hour sitcom, The Paul Lynde Show, to the network for the 1972–1973 season. In a parody of her Samantha Stephens role, she made a cameo appearance as a witch at the end of the beach party film How to Stuff a Wild Bikini (1965).